I ran Mandrake for years, but when I put a new hard drive in my laptop, I decided to start over (well, "decided" should really read "was forced by some unknown quirk"). I used Knoppix via live CD to poke around the filesystem and make sure I had everything in the right place, but I decided to go with Ubuntu when I setup the installation to disk. Ubuntu is slick, and is usable much more readily than anything I've used before. Software updates are flawless and fast and everything works great. (Nothing against Knoppix; it has lots of fans, too, and would be a good distro too, I'm sure.)